Lusted: Will you upload the files? :) [please!]
Well some examples from the file:

Code:
projectile composite_arrow

effect			arrows_new_set
end_effect				arrow_impact_ground_set
end_man_effect			man_impact_tiny_set
end_package_effect    	arrow_impact_wall_set
end_shatter_effect		arrow_impact_ground_set
end_shatter_man_effect		man_impact_tiny_set
end_shatter_package_effect	arrow_broken_impact_wall_set

effect_offset	-1.5
damage		0
radius		0.1
mass		0.05
;accuracy_vs_units		0.0010
affected_by_rain
min_angle	-75
max_angle	45
velocity	20 48
display		aimed
effect_only
Notice the accuracy vs units line, i've removed the ; in my mod and it woks fine, so we can now edit projectile accuracy.